Generally such lamps are held, in a socket composed of insulating material, by spring elements having detents which engage behind cam surfaces formed on the lamp's insertion stem. Such a socket is described in U.S. Pat. No. 4,426,602 and corresponding German Patent Disclosure Document DE-OS No. 31 21 077, which discloses a socket having a plastic housing with a U-shaped metal strip inside, whose ends are bent into semi-circular detents which engage behind the cam surfaces on the insertion stem of the lamp. For reasons of electrical safety, it would be desirable to avoid such a construction, and to limit the metal components within the socket to those which are necessary to provide the electrical contact between the lamp base and the socket.